1. Technical Field
The present invention relates to a printing apparatus.
2. Related Art
An ink jet printer which performs printing by discharging ink from a plurality of nozzles has been known. In the ink jet printer, when a state where the ink is not discharged from the nozzle is maintained, moisture of the ink from the nozzle openings evaporates to increase the viscosity of the ink. When the viscosity of the ink is increased, the nozzles can be clogged to cause a discharge operation of the ink to become difficult. In order to prevent such problem from occurring, by performing so-called flushing, by the process of discharging the ink from each nozzle by force, it is preferable to prevent or remove clogging of the nozzle.
In the related art, an ink jet printer has been known which moves the nozzle to a position corresponding to a printing sheet and performs a recovery process by flushing to print a character and a picture in a rectangular shape (refer to JP-A-06-15815). In addition, a droplet discharging apparatus has been known, which prevents dot spread and an increase in density to make the dummy jet pattern difficult to be recognized by randomly disposing a dot in a dummy jet pattern formed on a sheet at intervals of one dot or more in an X or Y direction so that each dot may not be adjacent to each other or may not overlap each other (refer to JP-A-2007-136722).
In JP-A-06-15815, a printing speed is improved by performing flushing on a printing sheet more than by performing flushing on a waste ink absorber. However, since the character and the picture in a rectangular shape are printed by flushing on the printing sheet, there is a concern that a user may make a low evaluation for the printing result. In addition, even in the JP-A-2007-136722, since a dummy jet pattern is printed on a sheet by flushing when an image quality priority mode is not selected, degradation of an image quality is inevitable. On the other hand, in printing processing, whether a priority is given to a speed or an image quality depends on a user. In other words, there is a problem in accurately realizing the printing process according to the demand of a user for the printing speed or the image quality. Moreover, it has been required to realize the printing speed and the image quality at an optimal balance considering various conditions, which a user randomly selects with respect to printing, other environmental conditions, and the like.